/**
 * <p>Copyright: Copyright (c) 2014</p>
 * <p>Company: ---Technology Co. Ltd</p>
 * <p>2014-4-30</p>
 * @author Jan.Zhang
 */
package com.xianl.busiplat.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


/** 
 * desc:
 * <p>author: Jan.Zhang </p>
 * date: 2014-4-30
 */
public class VerifyCodeUtil {

	private static final int VERIFY_CODE_TYPE_NUMBER = 1;
	private static final int VERIFY_CODE_TYPE_LETTER_DEFAULT = 2;
	private static final int VERIFY_CODE_CHARS = 4;
	private static final int VERIFY_CODE_WIDTH_DEFAULT = 80;
	private static final int VERIFY_CODE_HEIGHT_DEFAULT = 20;

	public static void create(int type, String sessionVerifyCodeName, HttpServletRequest request,
			HttpServletResponse response) throws IOException {
		create(VERIFY_CODE_WIDTH_DEFAULT, VERIFY_CODE_HEIGHT_DEFAULT, type, sessionVerifyCodeName, request, response);
	}

	public static void create(String sessionVerifyCodeName, HttpServletRequest request, HttpServletResponse response)
			throws IOException {
		create(VERIFY_CODE_WIDTH_DEFAULT, VERIFY_CODE_HEIGHT_DEFAULT, VERIFY_CODE_TYPE_LETTER_DEFAULT,
				sessionVerifyCodeName, request, response);
	}

	public static void create(int width, int height, int type, String sessionVerifyCodeName,
			HttpServletRequest request, HttpServletResponse response) throws IOException {
		response.setContentType("image/jpeg");
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		// HttpSession session=request.getSession(false);
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		Graphics g = image.getGraphics();
		Random random = new Random();
		Font mFont = new Font("Arial", Font.PLAIN, 18);
		g.setColor(getRandColor(140, 220));
		g.fillRect(1, 1, width, height);
		g.setFont(mFont);
		g.setColor(new Color(173, 197, 222));
		g.drawRect(0, 0, width - 1, height - 1);
		for(int i = 0; i < 20; i++) {
			g.setColor(getRandColor(170, 222));
			int x = random.nextInt(width - 1);
			int y = random.nextInt(height - 1);
			int xl = random.nextInt(6) + 1;
			int yl = random.nextInt(12) + 1;
			g.drawLine(x, y, x + xl, y + yl);
		}
		for(int i = 0; i < 20; i++) {
			g.setColor(getRandColor(150, 222));
			int x = random.nextInt(width - 1);
			int y = random.nextInt(height - 1);
			int xl = random.nextInt(12) + 1;
			int yl = random.nextInt(6) + 1;
			g.drawLine(x, y, x - xl, y - yl);
		}
		String sRand = "";
		for(int i = 0; i < VERIFY_CODE_CHARS; i++) {
			String randTemp = "";
			if(VERIFY_CODE_TYPE_NUMBER == type ) {
				randTemp = String.valueOf(random.nextInt(10));
				sRand += randTemp;
			} else {
				randTemp = getRandomChar();
				sRand += randTemp;
			}
			g.setColor(new Color(20 + random.nextInt(160), 20 + random.nextInt(120), 20 + random.nextInt(150)));
			g.drawString(randTemp, 15 * i + 10, 15);
		}
		request.getSession().setAttribute(sessionVerifyCodeName, sRand);
		g.dispose();
		ServletOutputStream responseOutputStream = response.getOutputStream();
		ImageIO.write(image, "JPEG", responseOutputStream);
		responseOutputStream.flush();
		responseOutputStream.close();
	}

	public static Color getRandColor(int fc, int bc) {
		Random random = new Random();
		if(fc > 255 )
			fc = 255;
		if(bc > 255 )
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

	private static String getRandomChar() {
		int rand = (int) Math.round(Math.random() * 2);
		long itmp = 0;
		char ctmp = '\\';
		switch(rand) {
			case 1:
				itmp = Math.round(Math.random() * 25 + 65);
				ctmp = (char) itmp;
				return String.valueOf(ctmp);
			case 2:
				itmp = Math.round(Math.random() * 25 + 97);
				ctmp = (char) itmp;
				return String.valueOf(ctmp);
			default:
				itmp = Math.round(Math.random() * 9);
				return String.valueOf(itmp);
		}
	}
}
